Apparatus for producing curled yarn



Feb. 18, 1958 L VANDAMME ETAL APPARATUS FOR PRODUCING CURLED YARN 3 Sheets-Sheet 2 Original Filed June 11, 1954 INVENTOR Law/s l A A/pA M/VE A Trap/W5) Feb. 18, 1958 1.. VANDAMME ETAL 2,823,514

- APPARATUS FOR PRODUCING CURLED YARN v Original Filed June 11, 1954 i 5 Sheets-Sheet 3 INVENTORS Lou/5 MAAm/IMME i 2,823,514 Psiten'tedFeb. 1:8, "195% APPARATUS FOR PRODUCING CURLED Louis Vandamme and Louis Rouyer, Saulce, France, as-

signoi's to Moulinage et Retorderie de Chavanoz, Chavanoz, France, 'a' corporation of France Original application June 11; 1954,;Serial No. 436,077, now Patent No. 2,761,272, --dated"September* 1 95 6. Divided and this application July 11','1956, Serial 'No. 597,303

Claims priority, application France June 19, 1953 1 Claim. (CI. 57-34) This invention relates to the production of a curled yarn and more particularly to apparatus for setting a false twist in a continuously advancing yarn.

This application is a division of my copending application Serial No. 436,077 filed June 11, 1954 now U. S. Patent No. 2,761,272.

An object is to provide a novel and improved apparatus of the above type.

Copending application Serial No. 331,158 filed January 14, 1952 now U. S. Patent No. 2,741,893 discloses a method of producing a curl which involves passing the yarn through a false twister, allowing the false twist to travel along the yarn in a direction counter to the direction of feed, and setting the twist so produced by hot water or steam.

The present invention provides improved apparatus for setting the false twist thermally and in a dry state, i. e. without subjecting the yarn to hot water or steam. The setting is effected for example by contacting the yarn with a plate heated by the internal circulation of a hot fluid such as oil, or by subjecting the yarn to heating by a high frequency electric field, or to a bank of lights or burners emitting infra red rays.

The nature of the invention will be better understood by referring to the following description, taken in connection with the accompanying drawings in which certain specific embodiments have been set forth for purposes of illustration.

In the drawings:

Fig. 1 is a front elevation of an apparatus for setting the false twist by contacting the yarn with a heated member;

Fig. 2 is a side elevation thereof;

Fig. 3 is a side elevation of a portion of an apparatus for heating the yarn by a high frequency field; and

Fig. 4 is a side elevation of a portion of an apparatus for heating the yarn by infra red radiations.

Referring to Figs. 1 and 2 of the drawings more in detail the yarn 8 which is of the thermoplastic type and may for example constitute polyhexamethylene adipamide is unwound endwise from a bobbin 1 and is passed through a friction device 2, shown as of the grid type, although any other suitable type of friction drag may be used. From the friction device 2, the yarn passes between a feed roll 3 and a presser roll 9. The roll 3 is driven from main shaft A through bevel gears B and C and through a gear train comprising gears 4, 5, 6 and 7. The main shaft A may be driven from any suitable source of power, not shown.

From the feed rolls the yarn passes over a guide roll 10 and in contact with the outside of a hollow curved metal casing 11 and through a guide eyelet 10. The curvature of the metal casing 11 is such that the yarn is caused to contact the casing for a substantial distance in its travel. The hollow casing is connected by ducts 11a and 11b to a heating device 12 such as a boiler containing a fluid which is maintained at constant tempera- 2 ture byi'a therm'ostat, not shownyandis capable 'ofjw'ith, standing'jtemperaturesof more than 200 C., for'example mineral '-oil,Dowothe rm,"" orv the like; The temperature of the fluid must be maintained -belov'v the melting point of the polymer from which the yarnis made. A pump 13 delivers the" hot liquid through the. duct 11a into'the interior ofthe' hollow casing? 11, whence'it' re- Excessive heatloss isj'preve'nted by a, reflecting" ins'u} lated'wo'ver plate 11c"which"is"disposd on'th'e' side of the casing 11 over which the yarn 8 passes or reflects heat from the casing onto the yarn.

The boiler 11 may supply hot liquid to a plurality of casings 11 which may constitute a bay or side of a frame thereby insuring complete uniformity of temperature applied to all yarns of the frame.

From the eyelet 10' the yarns 8 pass into a false twister 14 of standard construction which is shown as driven by a belt from the main driving shaft A. The twister 14 includes a rotary member which causes rotation of the yarn passing therethrough and thereby imparts a false twist which travels downwardly along the yarn counter to the direction of feed and produces a twist in the portion of the yarn in contact with the heated casing 11. The temperature of the casing 11 is controlled to heat the yarn in contact therewith to a temperature suited to set the twist in the yarn so that as the yarn passes upwardly beyond the false twister 14 and is again unwisted, the curl produced by the set twist remains in the individual filaments.

From the false twister 14 the yarn 18 passes to a Winding bobbin 16 which is driven by contact with a driven roller 15. The roller 15 is driven from the main shaft A through bevel gears D and E and a gear train comprising gears 17, 18, 19 and 20. The bobbin 16 is mounted on a pivoted bracket 20 so that the winding rests on the driving roll 15 and is driven thereby to wind the yarn at a constant peripheral speed. A traversing guide 21 guides the yarn 8 onto the bobbin 16.

Transmission ratios between the shaft A and the rollers 3 and 15 are so selected as to permit any desired shrinkage to take place in the yarn 8 between the two sets of rolls. Since the various rolls of a given frame may be driven from the same shafts the shrinkage will be maintained the same for all of the yarn treating stations of the frame. The shrinkage in length is normally because of the twist which is imparted to the yarn by the false twister and the ratio of the rolls 3 and 15 is selected in accordance with the desired characteristics of the product.

The above described mechanism produces a high curl in yarns from various thermoplastic materials, such as polyhexamethylene adipamide or polyacrylonitrile, or other materials having thermoplastic properties. Since the curl is set by dry heat due to the contact with the outside of a heated plate 11 it is completely stable.

A further embodiment of the invention is shown in Fig. 3 in which the various parts which correspond to the parts of Figs. 1 and 2 have been omitted. In Fig. 3 the apparatus is the same as in Figs. 1 and 2 except that the heated casing 11 is replaced by a pair of electrodes F between which the yarn passes in its travel from between the guide roll 10 and the false twister 14. A source G of very high frequency current is connected to the electrodes P so that a high frequency electrostatic field is produced which is adapted to heat the yarn to the temperature necessary for setting as it passes the electrodes. The treatment is otherwise similar to that described in connection with Figs. 1 and 2.

In Fig. 4 the apparatus is assumed to be identical with that'in Figs. 1 and 2 except that the heated casing 11 of Figs. 1 and 2 is replaced by a bank of infra red heat I source 22 which are disposed to apply infra red heat onto the yarn 8 as it passes from the roll 10 to the false twister.

While certain specific embodiments have-been illustrated it is to be understood that various changes and adaptations may be made therein as will be apparent to a person skilled in the art.

What is claimed is:

An apparatus for producing a curled yarn from a bundle of synthetic thermoplastic filaments comprising a false twister, feed rolls for feeding yarn to said false twister, a bobbin on which the yarn is wound after passingthrough said false twister, means driving said feed rolls and said bobbin at a predetermined speed ratio for maintaining a constant predetermined shrinkage in said bundle, and a source of infra red radiations disposed along the path of the bundle between said feed rolls and said false twister to apply dry heat to the bundle suited to heat the bundle to a temperature to set the curl therein.

References Cited in the file of this patent UNITED STATES, PATENTS 2,696,034 Swartz Dec. 7, 1954 2,761,272 Vandamme et a1 Sept. 4, 1956 2,777,276 Klein Jan. 15, 1957 

